JP5305603B2 - Railway rail fastening bolt looseness inspection device - Google Patents

Description

  The present invention relates to a rail rail fastening bolt looseness inspection device that automatically detects the looseness of rail fastening bolts in a railroad, and in particular, a railroad that can be mounted on a track check vehicle and inspected for looseness of fastening bolts while traveling at high speed. The present invention relates to a rail fastening bolt looseness inspection device.

A rail fastening device in a railway fixes a rail by pressing it from both sides of a rail base with a tip of a leaf spring. The leaf spring secures a pressing force by crimping the central portion onto the sleeper with a fastening bolt. Therefore, if the rail fastening bolt is loosened, the tip of the leaf spring will be lifted from the rail base, causing the rail to slip sideways or the rail pad for adjusting the height of the rail to come off, leading to a serious accident. . For this reason, it is necessary to periodically inspect the fastening bolts for looseness.
Looseness inspection of fastening bolts is usually carried out at night when train operation is low, by visual observation and observation of hammering sound, and thus requires a large number of skilled maintenance workers and may be overlooked due to human power.

On the Shinkansen, the first train is operated every morning after confirming that there are no abnormalities in the rails and overhead lines by running track confirmation vehicles in each ward.
It would be convenient if a rail check bolt looseness inspection device could be installed in the track confirmation vehicle to monitor the bolt looseness. Moreover, if the state of the rail is grasped on a daily basis using an automatic inspection device, it is useful for preventive maintenance.

Patent Document 1 discloses a method of continuously inspecting rail fastening bolt looseness by installing a device for measuring the height of fastening bolts under the floor of a track checking vehicle.
The rail fastening bolt looseness detecting device disclosed in Patent Document 1 is a rail sensor that measures the distance to the rail head top surface with a laser displacement meter and the distance to the head of the fastening bolt that sandwiches the rail with the laser displacement meter. A pair of bolt sensors to be measured are arranged, and the looseness of the bolts is detected from the difference between the measured values of the bolt sensor and the rail sensor. If looseness is found, it can be dealt with by reflecting it in maintenance work, such as retightening at the latest opportunity.

Since the track confirmation vehicle operates at a high speed of about 110 km / hr, the vehicle moves up and down. Therefore, the distance to the fastening bolt head changes drastically during operation, and accurate measurement is difficult when using a distance meter.
The invention of Patent Document 1 attempts to accurately evaluate the looseness of the bolt by calculating the height of the bolt head with reference to the rail head.

  However, since the Shinkansen track confirmation vehicle travels at 110 km / hr, it is inevitable that the measurement position changes in the horizontal direction due to the vehicle shaking. In addition, there are a plurality of types of leaf springs for restraining the rail, and the position of the fastening bolt changes if the types of leaf springs are different. The relationship between the vehicle body and the bolt position fluctuates by about ± 30 mm in the horizontal direction due to the fluctuation of the vehicle and the type of fastening device. Therefore, in order to reliably capture the measurement target, a margin of ± 30 mm is required in the measurement range.

In the rail fastening bolt looseness detection device disclosed in Patent Document 1, the measurement position of the laser displacement meter provided immediately above the bolt often deviates from the head of the bolt while the track check vehicle is running. Further, the bolt position depending on the type of fastening device may fluctuate and deviate from the measurement range of the laser displacement meter.
As a sensor that can cope with such fluctuations and deviations, there are a method of mechanically scanning a laser and a method of monitoring a wide range by optical cutting measurement using slit light. However, these methods complicate information processing. It is not possible to obtain a simple device for completing measurement during high-speed traveling.
JP 9-315304 A

  The problem to be solved by the present invention is an apparatus for inspecting the looseness of a rail fastening bolt while traveling under a floor such as a track confirmation vehicle, and inspects even if there is a change in the position of the fastening bolt or a vehicle shake. It is to provide a rail rail fastening bolt looseness inspection device capable of performing the above.

The rail rail fastening bolt looseness inspection device of the present invention is a device that includes a line sensor, a plurality of spot laser projectors, a laser lighting circuit, an image input circuit, and a determination circuit in order to solve the above-described problems. Here, the line sensor is arranged so that the top surface of each of the pair of fastening bolts sandwiching the rail tread surface and the rail enters the field of view, and the plurality of spot laser projectors and the detection axes of the line sensor are in one plane. At least one of the spot laser projectors is arranged at a position where the laser beam projected therefrom is reflected by the rail tread surface, and the other spot laser projector is for each of the pair of fastening bolts sandwiching the rail. multiple, provided the same number, each of the top surface delle laser light of the fastening bolts of the pair at the time of measurement is at least one is arranged at a position to reflect. Further, the laser lighting circuit circumferential-term driving sequence, the fastening bolt of a pair sandwiching the rail during one frame photographed by exciting sequentially switches sequentially switched excitation spot laser projector spot laser projector turning on the spot laser projector for projecting a laser beam to at least any Lumpur tread during one cycle of against Teso respectively at most one spot laser projector only lights lest vital driving sequence. Furthermore, the image input circuit inputs an image indicating the laser beam reflection position from the line sensor every time the laser is switched on and outputs information on the laser beam reflection position, and the determination circuit obtains the laser beam reflection position of the acquired image. Based on the height of the top surface of the fastening bolt and the height of the rail tread, the looseness of the fastening bolt is detected and the result is presented.

The rail rail fastening bolt looseness inspection device of the present invention is a line sensor that detects the position where a spot laser emitted from a plurality of spot laser projectors arranged so as to be in one plane with the detection axis of a line sensor hits the track floor and reflects it. Shoot with.
Based on the reflection position in the image of the line sensor and the irradiation direction of the spot laser, the height of the reflection surface can be obtained using the principle of triangulation. As the vehicle moves up and down, the distance between the line sensor and the reflective surface changes, and the measured value changes.However, by determining the height of the reflective surface based on the height of the rail tread, the effect of the vertical movement of the vehicle can be reduced. The removed absolute value can be obtained.

  One spot laser projector is disposed at a position where the emitted laser light is reflected by the rail tread. Since the rail tread has a large width, a spot laser always strikes and reflects even if there is some fluctuation. Therefore, the spot laser reflection position on the rail tread is always reflected in the line sensor image acquired immediately after the rail tread irradiation spot laser projector is turned on.

  Therefore, in the present invention, a plurality of spot laser projectors are used for one bolt to widen the measurement range. For example, if three spot laser projectors are used for fastening bolts on one side of the rail and the horizontal distances between the laser beams are 30 mm apart, the top surface of the fastening bolt will always have one or more reflections. Light can be observed. Since the bolt head has a diameter of 35 mm, it appears when two reflection spots can be observed.

As described above, the spot laser projector for bolts is arranged at a position where at least one of the radiated laser beams is reflected at the top surface of each of the pair of fastening bolts sandwiching the rail at the time of measurement. When doing so, one reflected light on the top surface of the bolt is always captured.
From the spot laser projector position and the spot laser reflection position, the height of the rail tread and the height of the bolt top is calculated in the manner of triangulation. When the difference from the height of the bolt top surface is calculated based on the rail tread height, the head height of the fastening bolt can be accurately obtained even when the vehicle moves up and down. Based on this value, bolt looseness is evaluated.

  Instead of obtaining the top surface height by performing triangulation calculation for each measurement, the relationship between the top surface height and the pixel position of the line sensor that captures the reflection point is calibrated in advance for each spot laser projector. The height of the top surface can be obtained directly from the pixel position where the reflection point is captured.

If all spot laser projectors emit laser simultaneously, the reflection positions appearing in the screen acquired by the line sensor are congested, and it becomes difficult to determine which projector each reflection position is from.
Therefore, in the present invention, the laser spot appearing in the video is limited by sequentially switching the spot laser projectors and turning them on with the laser lighting circuit. Further, by acquiring the video output of the line sensor in synchronization with the lighting timing, it is possible to obtain an image in which only the laser light reflection position by the lit projector is reflected. With reference to the lighting timing, it is possible to identify the spot laser projector that has irradiated the laser spot in the acquired image.

It is preferable that the laser lighting circuit lights the spot laser projector by a periodic driving sequence with lighting of the spot laser projector that projects laser on the rail tread as a break.
When lighting the projector that projects the laser on the rail tread, only the rail tread projector may be turned on, or may be turned on together with a specific bolt projector. In any case, since the number of reflected spot lights is different, this timing can be determined.
In addition, since there is little possibility of causing confusion between two bolts arranged with the rails sandwiched between the bolt projectors, two projectors with the rails sandwiched can be turned on at one lighting timing. .

In addition, the determination circuit can determine the presence or absence of looseness based on the minimum value of the difference between the height of the top surface of the fastening bolt and the height of the rail tread.
There is nothing in the vicinity of the rail that is usually higher than the fastening bolt. Therefore, the bolt top surface height can be easily determined by the maximum value of the detected measurement values.
The interval between the lighting command pulses can be set to about 30 kHz including the steps of spot laser projector lighting, line sensor image acquisition, image analysis, and determination. At this pulse rate, measurements can be made at 1 mm intervals at a vehicle speed of 110 km / hr. In a configuration in which three spot laser projectors for bolts are provided with the rails in between and the lamps are sequentially turned on, the height data is collected at intervals of 3 mm.

Since rail fastening bolts on the Shinkansen are usually installed at intervals of about 600 mm, the bolts are not detected at many measurement timings, but the top height of the fastening bolts can be reliably measured at the positions where the bolts are present. it can.
In addition, since the railroad rail fastening bolt looseness inspection device of the present invention is necessary for each rail, it is provided on each side of the vehicle.

Hereinafter, the best mode of a railroad rail fastening bolt looseness inspection device of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of a sensor portion of the railroad rail fastening bolt looseness inspection device of this embodiment, FIG. 2 is a block diagram of a measurement circuit portion of the railroad rail fastening bolt looseness inspection device of this embodiment, and FIG. 3 is a sensor of the inspection device. FIG. 4 is a diagram for explaining the principle of measuring the height of the top surface of this embodiment, FIG. 5 is a table showing an example of a lighting schedule in this embodiment, and FIG. 6 is a time showing a signal change during measurement. FIG. 7 is a table showing another example of the lighting schedule in this embodiment.

FIG. 1 is a block diagram showing that the sensor portion of the railway rail fastening bolt looseness inspection device of this embodiment is inspected for looseness facing the rail fastening bolt, and FIG. 2 is a block diagram of the measurement circuit portion. .
The rail rail fastening bolt looseness inspection device according to the present embodiment is shown in FIG. 1. A rail fastening device in which the center portion of a leaf spring is crimped onto a sleeper with a fastening bolt and the base portion of the rail is pressed down by the tip portion of the leaf spring. This is a device for detecting looseness of a fastening bolt.

  As shown in FIG. 1, the sensor part of the railway rail fastening bolt looseness inspection device of this embodiment is composed of a line sensor 1 and a spot laser projector 2, and a protective housing provided with a multilayer glass 31 between the measuring object. 3. The double-glazed glass 31 has a double-glass structure that blocks the inside and outside air, prevents foreign matter from entering or colliding with the sensor part, and condenses on the glass due to a temperature difference between the inside and outside and becomes opaque. There is an effect to prevent.

FIG. 3 is a bottom view of the sensor portion.
The spot laser projector 2 is arranged so as to be aligned on the sensor axis of the line sensor 1 in order to observe all the reflected light with one line sensor 1 arranged in the center of the protective housing 3. The spot laser projector 2 is installed obliquely so that the laser beam is inclined inward.

The protective housing 3 is disposed on the left and right floors of a track confirmation vehicle (not shown), one set each facing the rail portion, and the visual field of the line sensor 1 is a fastening bolt disposed on both sides of the rail with the rail tread 41 as the center. It is fixed so as to include the top surface 42.
As shown in the drawing, the rail is fixed by pressing the base at the tip of a leaf spring 44 that is crimped onto a sleeper 43 with a fastening bolt.

The line sensor 1 is a one-dimensional CCD camera having an optical cell of 1024 pixels, for example, and is driven by a pulse of 31 kHz, for example, and outputs a one-dimensional image of one frame for each pulse.
The spot laser projector 2 includes a rail projector L0 that irradiates the rail tread 41, and bolt projectors L1, L2,..., L6 that irradiate the fastening bolt top surface 42. The bolt light projectors are divided into two groups arranged in contrast with each other across the rail. For example, as shown in the figure, three light projectors L1, L2, L3; L4, L5, and L6 are used.

  The looseness of the fastening bolt is determined by measuring the height of the bolt top surface 42. The height of the bolt top surface 42 is obtained by detecting the light spot formed by reflecting the laser beam from the spot laser projector 1 that has captured the target bolt top surface on the top surface with the line sensor 1. It can be calculated by the principle of triangulation.

  The reason why three bolt projectors are combined is to allow other spot lasers to capture the target and perform measurement even if the vehicle body shakes left and right and the spot laser comes off the target. Therefore, it goes without saying that the number of combinations is not limited to three.

In a track confirmation vehicle traveling at 110 km / hr, the measurement position changes in the horizontal direction due to the shaking of the vehicle. Also, the bolt position varies depending on the type of fastening device. These fluctuation ranges are about ± 30 mm in total. Therefore, in order to prevent the fastening bolts from being overlooked regardless of these fluctuations, a margin of ± 30 mm is required in the measurement range.
In view of this, in the rail rail fastening bolt looseness inspection apparatus mounted on the track confirmation vehicle, the spot laser projectors having optical paths parallel to each other are shifted by about 30 mm in the horizontal direction.

  The rail projector is used to measure the distance to the rail tread that becomes the reference height when detecting looseness of the rail fastening bolt. By calculating the height of the top surface of the rail fastening bolt using the measured value of the rail tread as a reference value, the absolute height can be known by offsetting the influence of the vertical movement of the vehicle.

FIG. 4 is a diagram for explaining the principle of measuring the bolt top surface height.
The spot laser emitted from the tip L of the spot laser projector 2 hits the surface of the object and is reflected. The light reflected by the spot laser irradiation point R passes through the optical center C of the line sensor 1 and is captured by the CCD sensor 11, and the light is accumulated in the optical cell D at a position determined by the incident angle of the reflected light. Note that the spot laser projector 2 is arranged in the direction of the optical axis of the CCD sensor 11. In the figure, the CCD sensor 11 inside the line sensor S is displayed as a map 12 that is equivalently enlarged to the corresponding position outside the object.

Since the positional relationship between the optical center C of the line sensor 1 and the tip position L of the spot laser projector is fixed and the irradiation direction of the spot laser is fixed, the CCD sensor on which the laser spot at the spot laser reflection position R is projected The relationship between the position of the eleventh optical cell D and the distance H between the object surface reflected by the spot laser and the optical center C is uniquely determined.
For example, as shown in FIG. 4, with respect to the optical cell D projected by the reflection position R when the spot laser hits the sleeper surface 45, the reflection formed on the fastening bolt top surface 42 by entering the fastening bolt in the optical path. The optical cell D ′ on which the point R ′ is projected is closer to the outside.

Thus, since the distance H to the reflection point R corresponds to the position of the optical cell D that captured the reflection point R, it can be obtained immediately from the output of the line sensor 1.
Although the relationship between the distance H to the reflection point R and the position of the optical cell D can be obtained by calculation, it varies depending on the installation position of the spot laser projector 2 and the laser light projection direction and requires complicated calculation. Each spot laser projector may be determined by calibrating by performing an actual test.

The result of the calibration is stored in the measuring device as a correspondence table between the position of the optical cell determined for each spot laser projector and the height of the reflecting surface, and is used when obtaining the distance to the reflecting surface from the measurement result.
If the distance H to the reflection point R is known in this way, the absolute height of the reflection point R can be calculated by obtaining the difference Δh from the distance to the rail tread 41.

However, if the reflected light from the seven spot laser projectors 2 is incident on the line sensor 1 at a time, it is difficult to specify the projector corresponding to the reflected light. Therefore, while shooting one frame with the line sensor 1, a sequence is set up so that only one spot laser projector is lit on each of the right and left fastening devices sandwiching the rail, so that the correspondence between the reflected light position and the projector can be simplified. It can be taken.
The spot laser irradiated to the rail tread 41 is turned on once every three spot laser projectors 2 to measure the distance to the rail tread 41, and the height of the fastening bolt top surface 42 is calculated. The standard.

FIG. 5 is a chart for explaining an example of a lighting schedule of the spot laser projector 2, and FIG. 6 is a timing chart of signals at the time of observation.
The first frame is a frame for measuring the rail C. The distance from the line sensor 1 to the rail tread 41 is calculated based on the CCD cell position information in which the rail projector L0 is turned on and the reflection point on the rail tread 41 is reflected. Ask.
The frame is defined by the drive pulse P of the line sensor 1.

In the second frame, the first bolt projectors L1 and L6 are turned on for the respective fastening devices Bl and Br on the left and right sides, and the line sensors 1 to the reflection points are determined based on the position information of the CCD cells that reflect the reflection points. Find the distance. Further, the height of the reflection point is calculated by subtracting the distance to the rail tread previously obtained.
In the third frame, the second bolt projectors L2 and L5 are similarly turned on, the distance to the reflection point is obtained, and the height of the reflection point with respect to the rail tread is calculated. In the fourth frame, the distance to the reflection point is obtained by the last bolt projectors L3 and L4, and the height of the reflection point with respect to the rail tread is calculated.
In the fourth frame, the process returns to the beginning again, and the rail light projector L0 is turned on to determine the distance to the rail tread.
Hereinafter, the same process is repeated, and the reflection point height at the position where the fastening device is located is measured.

Even in the place where the fastening bolt exists, all the three bolt light projectors 2 do not capture the bolt top surface 42. Therefore, the highest value among the obtained three data is adopted as the height of the bolt top surface.
Furthermore, based on the obtained bolt top surface height data, when a bolt that is higher than a predetermined reference value (for example, 5 mm) is found in comparison with the normal value, it is determined that the bolt has loosened. Then, the information is notified together with the bolt position information.
The position information can be obtained by using a kilometer measuring device installed on the wheel of the track confirmation vehicle.
The maintenance worker can perform preventive maintenance by obtaining the positional information of the loosened bolt and taking measures such as early tightening.

As shown in FIG. 7, the lighting of the light projector L0 for detecting the rail tread 41 is simultaneously performed with the lighting of the light projector for the bolt, so that the measurement cycle can be shortened and higher density measurement can be performed. it can. Although three light spots are imprinted in the first frame, they can be distinguished from each other.
In addition, Shinkansen sleepers are provided approximately every 600 mm, and rail fastening bolts exist only for each sleeper, but usually there are no tall objects other than rail fastening bolts in the vicinity of the rails. Even if it is determined that the highest position of the reflected light is the position of the bolt top surface, there is no problem.

  FIG. 2 is a block diagram for explaining the function of the measurement circuit unit that drives the sensor portion of FIG. 1, collects measurement signals, calculates the height of the reflecting surface, and determines and outputs the looseness of the fastening bolt. is there.

The pulse generator 51 supplies drive pulses to the lighting controller 52 and the image acquisition circuit 53 synchronously. Assuming that the drive pulse is 31 kHz, for example, when the railway rail fastening bolt looseness inspection device is mounted on a track confirmation vehicle traveling at 110 km / hr, the output scanning of the line sensor 1 can be performed every 1 mm.
The lighting controller 52 sequentially supplies power to the multiple projectors 2 in accordance with a predetermined lighting sequence. The sensor portion illustrated in FIG. 1 is provided with seven spot laser projectors, but each of the one that irradiates the rail tread 41 and the one that detects the height of the bolt top surface 42 functions correctly. The sequence is determined.

The image acquisition circuit 53 is also called a frame grabber, and is a circuit that acquires an image signal generated by the one-dimensional CCD sensor of the line sensor 1 and displays the image. The apparatus of this embodiment fulfills the function of detecting the pixel position of the CCD sensor that detects the reflected light position when the spot laser projector is turned on.
The output of the image acquisition circuit 53 is input to the determination circuit 54. The determination circuit 54 refers to the cell position reflecting surface height correspondence table stored in advance in the correspondence table storage device 55, and based on the position of the cell where the reflected light is detected, the rail tread surface 41 and the two regions sandwiching the rail are The distance measured from the sensor portion at the reflection point position is calculated, and the height of the fastening bolt is calculated from the difference between the distance to the rail tread surface 41 and the distance to the top surface 42 of the rail fastening bolt. Further, whether or not the fastening bolt is loose is determined based on the measured height of the bolt top surface 42.

The track check vehicle is provided with an instrument for calculating the travel distance by integrating the axle pulses obtained by setting the encoder on the axle. Therefore, in the railway rail fastening bolt looseness inspection device according to the present embodiment, a system for identifying the position of the abnormal bolt using this axle pulse is constructed. Axle pulses are input from the rotation detector 56 that is an encoder, integrated by the counter 57, and supplied to the determination circuit 54 as travel distance information.
The determination circuit 54 can identify and display the position of the fastening bolt that has been loosened based on the travel distance.

  The determination circuit 54 does not perform the determination of the looseness of the fastening bolt, but generates the height information of the fastening bolt top surface using the cell position reflecting surface height correspondence table in real time, and the travel distance information converted into the kilometer. As a set, and may be written in the external storage device 58 such as a hard disk or a USB memory card and processed by the ground side detection processing computer.

  The rail rail fastening bolt looseness inspection device of the present invention can automatically inspect the rail fastening bolts for looseness without being overlooked even if the vehicle is moved up and down or horizontally, only by being fixed to the vehicle and running. Even when applied to Shinkansen track confirmation vehicles, etc., it is possible to detect the looseness of bolts without dropping by high-density inspection.

It is a block diagram of the sensor part of the railroad rail fastening bolt looseness inspection device concerning one example of the present invention. It is a block diagram of the measurement circuit part of the railroad rail fastening bolt looseness inspection apparatus of a present Example. It is a bottom view of the sensor part in a present Example. It is a diagram explaining the top face height measurement principle in a present Example. It is a table | surface which shows the example of the lighting schedule in a present Example. It is a time chart which shows the signal change at the time of the measurement in a present Example. It is a table | surface which shows another example of the lighting schedule in a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Line sensor 11 CCD pixel 12 CCD pixel mapping 2 Spot laser projector 3 Protection housing 31 Multi-layer glass 41 Rail tread 42 Fastening bolt top surface 43 Sleeper 44 Leaf spring 45 Sleeper upper surface 51 Pulse generator 52 Lighting control circuit 53 Image acquisition circuit 54 judgment circuit 55 correspondence table storage device 56 rotation detector 57 counter 58 external storage device

Claims (5)

A rail rail fastening bolt looseness detection device comprising a line sensor, a plurality of spot laser projectors, a laser lighting circuit, an image input circuit, and a determination circuit,
The line sensor is arranged so that the rail tread surface of the rail and the top surface of each of the pair of fastening bolts sandwiching the rail enter the field of view,
The plurality of spot laser projectors and the detection axes of the line sensors are arranged in one plane,
Wherein said at least one spot laser projector is arranged at a position where the laser light projected from the spot laser projector is reflected by the rail tread surface,
The other spot laser projectors are provided in plural and in the same number with respect to each of the pair of fastening bolts sandwiching the rail, and at least one laser beam is reflected from the top surface of each of the pair of fastening bolts during measurement. It is arranged at such a position, lights up with respect to the fastening bolt,
At most one of each to the fastening bolt of a pair sandwiching the rail while the laser lighting circuit is one frame captured by exciting sequentially switches the spot laser projector by circumferential-term driving sequence Only the spot laser projector is turned on , and the spot laser projector that projects laser light onto the rail tread at least once during one cycle of the drive sequence is turned on,
The image input circuit inputs an image indicating a position where the laser beam is reflected from the line sensor every time the spot laser projector is turned on , and outputs information on the laser beam reflection position ,
The decision circuit presents the detected result loosening of the fastening bolt on the basis of the height and the height of the rail tread top surface of said fastening bolt determined based on the laser beam reflecting position,
Railway rail fastening bolt looseness detection device. The rail rail fastening bolt looseness detecting device according to claim 1, wherein one spot laser projector is simultaneously turned on for each pair of fastening bolts sandwiching the rail. 3. The spot laser projector for projecting laser light onto the rail tread is lit simultaneously with the outermost spot laser projector for projecting laser light onto a pair of fastening bolts sandwiching the rail. Railway rail fastening bolt looseness detection device.   The said determination circuit determines the presence or absence of looseness based on the minimum value of the height of the top surface of the said fastening bolt with the height of the said rail tread surface. The rail rail fastening bolt looseness detection device described in 1. The railway according to any one of claims 1 to 4, wherein the position of the loosened fastening bolt is determined and shown in combination with a kilometer measuring device that determines the position of the vehicle by measuring the rotational speed of the wheel. Rail fastening bolt looseness detection device.

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